Glossary term
What is Strict Mode (React Strict Mode)?
Strict Mode stands for React Strict Mode.
In Scenario Debugging
A mode for development only. It renders twice and remounts effects once, to show impure code and missing cleanup.
Learn it properly · Scenario DebuggingLesson 5: Duplicate Requests, Race Conditions and Stale ResponsesStrict Mode running effects twice, double-click submits, responses that arrive in the wrong order, AbortController, removing duplicate requests, and idempotency keys on the server.In TypeScript From Zero
A group of compiler checks (such as strictNullChecks and noImplicitAny) that catch many mistakes.
Learn it properly · TypeScript From ZeroLesson 0: Why TypeScript, and Your First ProjectWhat TypeScript is and is not, why types are erased at runtime, setting up a project, a tsconfig explained line by line, and reading your first compiler errors.In React in Depth
A development-only wrapper that renders components twice and re-runs effects once to expose impure code and missing cleanup.
Learn it properly · React in DepthLesson 0: Thinking in React: Components, Props and JSXWhat React is, how JSX becomes function calls, components as functions, props, and the one-way data flow.